Posted
by
timothy
on Thursday August 04, 2011 @05:27PM
from the handy-clandestine-uses dept.

An anonymous reader writes "Scientists have developed a porous chip that can identify liquids instantaneously. Each liquid's distinct surface tension determines how much it seeps into the pores of the chip, which the chip uses to tell liquids apart. The researchers also decorated the chip with a secret message (ie, brand name) that only shows up when certain liquids are applied. The chip is so sensitive it can distinguish gasolines with varying proportions of ethanol, and could help clean-up crews identify spills in the field."

What would be truly interesting is if we the common people could check the percentage of ethanol when we fill up our gas tanks, or have it monitored within our gas tanks. Being able to tell at fill-up would actually tell you which gas station gives better gas. My money's on the chips being prohibitively expensive, though.

Flex Fuel vehicles already monitor this with a fuel composition sensor. It measures Ethanol content from 0-100% with a variable frequency between 50-150Hz, and Fuel temp with a pulse-width between 1 and 5ms.

And if you want to retrofit that capability to a vehicle, replace your ECU with a Megasquirt and hook up a Ford flex fuel sensor. You need to make sure your fuel lines can handle ethanol and your injectors can deliver enough fuel when running on 100% ethanol of course.

Even better - the car can itself sense it and adjust the engine management system depending on the quality of the fuel.

Right now the engine management systems are reactive, which means that they tune down the system when knocks occurs and at a regular basis it tries to tune up the system. A system that can predict the settings depending on fuel quality will provide even cleaner engines and better fuel economy.

If it effects the surface tension of the water (which surfactants do) then it should be able to identify it. It may not be able to register definitively what the surfactant is, but it should be able to identify the presence of one.

And you should atleast have some idea of what you're going through the trouble of throwing a sensor into.
Though this may be good for something like safety or for absorbing something and not something else.

So, I clicked through TFA and the link to the paper contained within. I'm not sure why Discover refers to this piece of hardware as a 'chip.' It doesn't appear to be an electronic chip of any sort. It looks like the information about what liquid the material is dipped in is derived from studying the patterns of 'wetness' within the material's structure. But I don't see any mention of how this information would be communicated via some electrical signal to a microprocessor or other circuitry. Perhaps I am thinking in a limited context, but it seems like this material's usefulness as a sensor is still very limited.

The term is also widely-used for microarrays [wikipedia.org] and other micro-labs [wikipedia.org]. Many of them are actually fabricated in silicon or other media like integrated circuits—the rectangle cut out of silicon wafer being the chip proper!

...but it seems like this material's usefulness as a sensor is still very limited.

If you can see it, so can an electric circuit. You see, there are these fancy things called photodiodes...
I mock, but in all seriousness, if you can map a measurable physical state to an unmeasurable physical state, then you might as well just skip the step and say, in this situation, something like "liquid chemical composition is measurable." The form the measurable information takes is irrelevant relative to the ability to measure it.

From the images it seems to not be that good at identification, unless I am not understanding it seems like it just gives a surface tension value.

In the case shown adding water to ethanol changes the reaction, however, mixes of water-ethanol would have the same surface tension as some other liquids, so how do you distinguish those, lets say acetone which is just a hair higher (in terms of S.T.) than ethanol vs ethanol+1%(or whatever makes it even) water